Intravenous versus intracuff alkalinized lidocaine to prevent postoperative sore throat: a prospective randomized controlled trial.

Introduction: postoperative sore throat (POST) is a common complication after general anesthesia with endotracheal intubation caused by tracheal mucosal injury. Multiple techniques prevent postoperative sore throat (POST). Our study aimed to compare two techniques: intravenous and intracuff lidocaine versus placebo to prevent postoperative sore throat after general anesthesia with orotracheal intubation.

Methods: we conducted a prospective double-blind, randomized controlled clinical trial involving patients, proposed for a scheduled surgery less than 240 minutes under general anesthesia with orotracheal intubation. Patients were divided into three groups: L group: infused with saline, cuff filled with alkalinized lidocaine. S group: Infused with 1.5 mg/kg of lidocaine, cuff filled with saline. T group: placebo: infused with saline, cuff filled with saline. Our primary outcome was the incidence of sore throat and their (visual analog scale) VAS score in the first 24 postoperative hours. Our secondary outcomes were the incidence of cough, dysphonia, dysphagia, and postoperative nausea and vomiting.

Results: ninety patients were analyzed and divided into 3 groups of 30. The incidence of POST at the sixth postoperative hour, for placebo, the "L" group, and the "S" group, respectively, was 67%, 30%, and 47%. And at the 24^th postoperative hours 67%, 13%, and 37%. Intravenous lidocaine reduced significantly the VAS of POST at the 24^th hour (S: 6.80 ± 20.70; T: 20.67 ± 18.182; p= 0.02). Alkalinized lidocaine decreased significantly the VAS of POST in the sixth (L: 8.17 ± 22.761; T: 23 ± 21.838; p = 0.048) and the 24^th postoperative hour (L: 6.33 ± 20.592; T: 20.67 ± 18.182; p= 0.019) with the lowest pain score. There was no statistically significant difference between the L and S groups at the 6 and 24 postoperative hours. Both lidocaine techniques reduced cough at emergence, with the superiority of alkalinized lidocaine (p=0.02). They decreased the incidence of cough, dysphonia, dysphagia, nausea, and vomiting compared to a placebo.

Conclusion: intravenous and intracuff lidocaine allowed better control of postoperative sore throat.